The O and H isotope characteristics of water from major rivers in China  

作　　者：Si-Liang Li Fu-Jun Yue Cong-Qiang Liu Hu Ding Zhi-Qi Zhao Xiaodong Li 

机构地区：[1]The State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences

出　　处：《Chinese Journal Of Geochemistry》2015年第1期28-37,共10页中国地球化学学报

基　　金：supported by National Natural Science Foundation of China (Grant Nos. 41210004 and 41130536);Chinese Academy of Sciences through grants KZCX2-EW-102

摘　　要：Isotopic compositions of the water sources and evapotranspiration in large rivers of China are not well explored. In this investigation, d18 O and dD values of water from major large rivers of China are integrated to understand the spatial and temporal variations in the isotopes of water and d-excess. River water samples were collected from the channels and tributaries of the Changjiang, Yellow, Songhua and Liao Rivers in China. Water from upstream was generally enriched with light isotopes relative to that from downstream areas. Water from the Songhua River and upper reach of the Changjiang River has relatively negative isotopic values impacted by latitude and altitude effects, respectively. The spatial pattern showed that d18O-H2 O values in rivers mainly ranged from-9 to-7 % in most of China based on roughly mapped contours, and rivers enriched in light isotopes were primarily located in the Tibetan Plateau and northeast China The slopes of linear regression from the Yellow and Liao Rivers suggested that the loss of water by direct evaporation shifted the isotopes of water, especially in some small tributaries. Additionally, there was a narrow range of low d18OH2 O values from the main channel of rivers during the lowflow season relative to the high-flow season due to influence of the monsoon climate. No distinct spatial variation of d-excess values was found in the rivers of China. However, water samples in some rivers with low d-excess values had high d18 O values, indicating that evaporation in the tributaries has led to significant water loss, especially in tributaries of the Yellow and Liao Rivers.Isotopic compositions of the water sources and evapotranspiration in large rivers of China are not well explored. In this investigation, δ18O and δD values of water from major large rivers of China are integrated to understand the spatial and temporal variations in the isotopes of water and d-excess. River water samples were collected from the channels and tributaries of the Changjiang, Yellow, Songhua, and Liao Rivers in China. Water from upstream was generally enriched with light isotopes relative to that from downstream areas. Water from the Songhua River and upper reach of the Changjiang River has relatively negative isotopic values, impacted by latitude and altitude effects, respectively. The spatial pattern showed that δ18O-H2O values in rivers mainly ranged from -9 to -7‰ in most of China based on roughly mapped contours, and rivers enriched in light isotopes were primarily located in the Tibetan Plateau and northeast China. The slopes of linear regression from the Yellow and Liao Rivers suggested that the loss of water by direct evaporation shifted the isotopes of water, especially in some small tribu- taries. Additionally, there was a narrow range of low δ18O- H2O values from the main channel of rivers during the low- flow season relative to the high-flow season due to influence of the monsoon climate. No distinct spatial variation of d-excess values was found in the rivers of China. However, water samples in some rivers with low d-excess values had high δ18O values, indicating that evaporation in the tributaries has led to significant water loss, especially in tributaries of the Yellow and Liao Rivers.

关 键 词：中国东北地区 同位素特征 河流 水源 长江上游 蒸发损失 同位素组成 时空变化 

分 类 号：P342[天文地球—水文科学]